RV-8523 Datasheet, PDF (45/57 Pages) MICORO CRYSTAL SWITZERLAND – Real Time Clock

Micro Crystal
Real Time Clock / Calendar Module
RV-8523
11.I²C BUS PROTOCOL
11.1. ADDRESSING
One I²C bus slave address (1101000) is reserved for the RV-8523. The entire I²C bus slave address byte is shown
in the table below:
I²C salve address byte:
Slave address
7
6
5
4
3
2
1
0
Bit
MSB
LSB
1
1
0
1
0
0
0
R/ W
After a START condition, the I²C slave address has to be sent to the RV-8523 device.
The R/ W bit defines the direction of the following single or multiple byte data transfer. In the write mode, a data
transfer is terminated by sending either the STOP condition or the START condition of the next data transfer.
11.2. CLOCK AND CALENDAR READ AND WRITE CYCLES
11.2.1. WRITE MODE
Master transmits to Slave-Receiver at specified address. The Word Address is 4-bit value that defines which
register is to be accessed next. The upper four bits of the Word Address are not used. After reading or writing one
byte, the Word Address is automatically incremented by 1.
1) Master sends out the “Start Condition”.
2) Master sends out the “Slave Address”, D0h for the RV-8523; the R/ W bit in write mode.
3) Acknowledgement from the RV-8523.
4) Master sends out the “Word Address” to the RV-8523.
5) Acknowledgement from the RV-8523.
6) Master sends out the “data” to write to the specified address in step 4).
7) Acknowledgement from the RV-8523.
8) Steps 6) and 7) can be repeated if necessary. The address will be incremented automatically in the RV-8523.
9) Master sends out the “Stop Condition”.
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